Question

Calcule a soma dos 5 primeiros termos da p.g (2‚4‚8‚16)

Answer 1

$> resolucao \\ \\ \geqslant progressao \: \: geometrica \\ \\ q = \frac{a2}{a1} \\ q = \frac{4}{2} \\ q = 2 \\ \\ \\ sn = \frac{a1(q {}^{n} - 1)}{q - 1} \\ \\ sn = \frac{2(2 {}^{5} - 1) }{2 - 1} \\ \\ sn = \frac{2(32 - 1)}{1} \\ \\ sn = \frac{2 \times 31}{1} \\ \\ sn = 62 \\ \\ \\ \\ \geqslant \leqslant \geqslant \leqslant \geqslant \leqslant \geqslant \leqslant \geqslant \geqslant \geqslant$

Answer 2

$\Large\boxed{\begin{array}{l}\sf S_n=\dfrac{a_1\cdot(q^n-1)}{q-1}\\\\\sf S_5=\dfrac{2\cdot(2^5-1)}{2-1}\\\\\sf S_5=\dfrac{2\cdot(32-1)}{1}\\\\\sf S_5=2\cdot31\\\\\sf S_5=62~\checkmark\end{array}}$